1. Technical Field
The present disclosure relates to device housings, and more particularly to a device cover for electronic devices and a method for fabricating the device cover.
2. Description of Related Art
Generally, metallic device covers present an appealing appearance and contact surface, and thus are popularly used for electronic devices such as mobile phones.
In a typical method for fabricating such a device cover, a metallic sheet is drawn into a preformed cover having a bottom base and a plurality of sidewalls extending substantially perpendicularly from a periphery of the bottom base. The preformed cover is upset by a forming die to thicken the sidewalls. The forming die includes a punch having a working surface extending perpendicular to an axis of the sidewalls. The sidewalls are machined by computerized numerical control (CNC) milling machines to complete the fabrication of the preformed device cover.
FIG. 9 shows a metallographic micrograph of an upset part of an aluminum alloy cover prepared by the above described method. It shows relatively disordered flow tracks of grains. Two large folds are formed by the flow tracks in sections A and B, and two distinguishable micro-cracks are formed in the middle of the two folds. As a result, the sidewalls exhibit diminished mechanical properties, such as low strength and stiffness, during machining by CNC milling machines.
What is needed, therefore, is a device cover that overcomes the limitations described. A highly efficient method of fabricating the device cover is also needed.